(NBC News) U.S. airstrikes in Iraq could continue this week. The ISIS threat is spreading, and U.S. lawmakers now fear the terrorist group could move its target.

“Mr. President, if you don’t adjust your strategy, these people are coming here,” said Senator Lindsey Graham (R-South Carolina).

The administration says there are no signs of a U.S.-aimed attack, but involvement is necessary to curb that risk. “Iraqis look at America as being able to help prevent a genocide, and we should do that,” said Senator Ben Cardin, (D-Maryland).

Over the weekend, there were more humanitarian airdrops for Yazidi Christians stranded on Sunjar Mountain, receiving thousands of pounds of food and water.

The State Department says it’s pulling out some American personnel in Erbil, citing an abundance of caution amid intense fighting and will explore options for evacuating stranded refugees.

Embattled Iraqi Prime Minister Nouri Al-Maliki spoke publicly for the first time Sunday since the U.S. airstrikes. He says he will not step down.

“Prime Minister Maliki has politicized the military and militarized the politics of Iraq over the last several years. That has to be reversed,” said Senator Jack Reed, (D-Rhode Island).

“And we can’t wait until Maliki and the Iraqi parliament to fight ISIS. Every day that goes by, ISIS builds up this caliphate, and it becomes a direct threat to the United States. They are more powerful now than al-Qaeda was on 9-11,” said Rep. Peter King, (R-New York).